Easily extract data from graphs
I use this tool all the time to (roughly) measure means, standard errors, etc. in plots I find online.
Confirm that your visualizations are accessible to people with color-blindness
Upload images of your plots to this website to check how people with different types of color-blindness perceive your chosen color palettes.
This website helped me identify a few academic papers related to perceptual restoration that I had overlooked during my literature search. (SOFT PAYWALL)
Or, things I’ve had to Google while using R.
Brittany N. Jaekel 